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A. Exercising mice and rats liked to learn new skills.
B. Exercising mice and rats remembered new skills better.
C. Mice and rats without exercise disliked learning new skills.
D. Mice and rats without exercise remembered new skills better.

A. He is not improving at all.
B. He has not won any games.
C. He has not played well recently.
D. He is not working very hard lately.

A. Because Jimmy doesn't have the right attitude.
Because Jimmy is kicking others out of the team.
C. Because Jimmy doesn't like to help other teammates.
D. Because Jimmy may make the team lose the championship.

A. He feels sick.
B. He has hurt his leg.
C. He doesn't know he's slow.
D. He doesn't have energy to run.